A team of astrophysicists reports a new method to detect quasars more efficiently. The new method is similar to that of the glasses to be worn in cinemas when watching a 3D movie: each eye is “fed” with light from a particular polarization, both vertical and horizontal.
With this method, researchers were able to identify the light coming from two different regions of the quasars, i.e. that of their discs and that of the jets, according to their different colorisation.
Quasars are huge supermassive black holes that see matter and gases orbiting around them at very high speed. Part of this matter and these gases, before passing the event horizon, bounces off and turns into two huge jets of plasma directed in the opposite direction at very high speed, close to the speed of light.
The two symmetrical jets are always clearly visible and it is essentially these two jets, plus the accretion disc, that allow the black hole itself to be detected. The two jets are ejected along the axis of rotation of the black hole.
Classic” telescopes detect quasars essentially as a tiny distant point and cannot distinguish between the light from the jets and the light from the accretion disc. Radio telescopes offer a slightly higher resolution and with them it is possible to detect the direction of the jets. However, the radio telescopes themselves cannot collect information about the accretion disc.
Yuri Kovalev, a researcher at the Moscow Institute of Physics and Technology, together with his colleagues, therefore thought to devise a new method by combining the strengths of both telescopes to discern the various polarizations of both the accretion disc and the jets.
The scientist himself states: “It was discovered that by measuring the polarization of the light collected by the telescope, we can tell which part of the radiation comes from the jet and determine its direction. This is similar to the way 3D glasses allow each eye to see a different image.